DESCRIPTION (Applicant's Abstract): This project verifies the effectiveness of a cartilage stiffness tester through a series of in vitro and in situ experiments. Utilizing non-destructive indentation, the proposed device will provide a rapid, accurate value for cartilage stiffness, which can then be correlated to its health. Our long-range goal is to commercially produce a clinical instrument for measuring articular cartilage stiffness. In this proposal, the objective is to test normal and degenerated cartilage and correlate it to traditional techniques for evaluating cartilage. This innovative project will complete the requisite work to show the utility of the instrument for detecting degenerative cartilage changes in human joints. Specific clinical indications include routine measuring of cartilage stiffness over time, early determination of cartilage disorders, and assessing outcomes from surgical operations. In Phase I, an integrated series of bench and animal studies will determine whether the instrument is sensitive enough to detect early degenerative cartilage changes, if it is dependent on cartilage thickness, and compare it to magnetic resonance imaging. Phase II will utilize the stiffness tester for in vivo human testing and establishment of a clinical database, for developing sterilization, and for finalizing instrument design. Large-scale manufacture will be optimized and marketing plans will be completed in Phase III. PROPOSED COMMERCIAL APPLICATION: No clinical instrument is available to quantify a loss in biomechanical properties of articular cartilage, which is one of the first signs of disease. The proposed non-destructive tester can measure cartilage stiffness to detect early degeneration allowing earlier intervention. Benefits of the device include quantifying cartilage degeneration, tracking of cartilage stiffness over time, and determining the extent of cartilage lesions. This instrument could be used in every arthroscopy to provide significant additional clinical information.